1. Field of the Invention
The present invention relates generally to an air conditioner housing for automobiles and air conditioner using the same, in which a two-layer recirculation air/fresh air flow partitioning structure is employed, so recirculation air/fresh air can be blown independently or in combination, the heating performance is improved, a white fogging can be prevented, and the defrosting performance is improved.
2. Description of the Related Technology
In general, an air conditioner for automobiles is comprised of a air cooling apparatus and a heating apparatus. The air cooling apparatus cools the passenger compartment in such a way that air blown by the blower fan of a blower unit is cooled by heat exchange with refrigerant flowing through an evaporator while refrigerant is compressed by a compressor operated by power transmitted from an engine, compressed refrigerant is condensed in a condenser by heat exchange with ambient air blown forcibly by a cooling fan and the condensed refrigerant is returned to the compressor through a receiver dryer, an expansion valve and an evaporator, and the cooled air is discharged to the passenger compartment. The heating apparatus heats the passenger compartment in such a way that air blown by a blower fan is heated by heat exchange with coolant flowing through a heater core while the coolant passes through the heater core and is returned to an engine and the heated air is discharged to the passenger compartment.
In FIG. 11, a general air conditioner for automobiles is illustrated. In this general air conditioner, an evaporator 910 and a heater core 920 are disposed in the inner air passage of an air conditioner housing 930, and a blower 940 is disposed at the entrance of the air conditioner housing 930. The blower 940 is comprised of a blower casing 942 integrated with the air conditioner housing 930, a blower fan 944 rotatably placed in the blower casing 942, a motor 946 operated to drive the blower fan 944, and an air intake duct 948 positioned in the upper portion of the blower casing 942 and provided with an recirculation air intake opening 952, and an fresh air intake opening 954 whose degree of opening is adjusted by a door 950. Accordingly, air flows into the blower casing 942 through the recirculation air intake opening 952 or the fresh air intake opening 954 by means of suction force generated by the rotation of the blower fan 944 by the operation of the motor 946, and is blown into the inner air passage, so air is changed into cold air or warm air by the heat exchange while passing the evaporator 910 and/or the heater core 920. A defrosting vent 932 for defrosting window glasses of an automobile by discharging warm air to the window, a face vent 934 for air-conditioning the passenger compartment by discharging cold or warm air to the passenger compartment, and a foot vent 936 for air-conditioning the passenger compartment by discharging cold or warm air to the floor of the automobile are disposed at the air outlet end of the air conditioner housing 930. The degrees of opening of the vents 932, 934 and 936 are adjusted by the doors 932d, 934d and 936d in accordance with predetermined air cooling and heating modes. Additionally, a temperature adjusting door 922 is positioned in front of the heater core 920 to adjust the degrees of opening of air passages extending through and over the heater core 920. Accordingly, in a air cooling mode, since the air passage extending over the heater core 920 is opened when the temperature adjusting door 922 closes the air passage extending through the heater core 920, air having passed through the evaporator 910 is discharged to the passenger compartment through opened vents without passing through the heater core 920, thereby cooling the passenger compartment. In contrast, in an air heating mode, since the air passage extending through the heater core 920 is opened when the temperature adjusting door 922 closes the air passage extending over the heater core 920, air having passed through the evaporator 910 is passed through the heater core 920 and discharged to the passenger compartment through opened vents, thereby heating the passenger compartment.
In the general air conditioning apparatus, recirculation or fresh air is sucked into a single air passage through an opened recirculation or fresh air intake opening 952 or 954, or recirculation and fresh air is sucked into a single air passage while being mixed together when the door 950 is in a neutral position. As a result, when only fresh air is supplied to the passenger compartment during the operation of the air conditioner, the load of a compressor is increased, thereby increasing the consumption of fuel; whereas when recirculation air is circulated, air in the passenger compartment becomes contaminated, thereby injuring passengers' health. Additionally, when a mixture of recirculation and fresh air is supplied, the heating performance of the air conditioner is improved in comparison with the case where only fresh air is supplied, but passengers cannot enjoy the freshness of fresh air and the defrosting performance of the air conditioner is deteriorated because of the humidity of recirculation air.
In order to overcome the above-described shortcomings, there have been proposed air conditioners in which recirculation and fresh air is supplied to the passenger compartment in independent or combinational manner according to air cooling and heating modes.
Japanese Pat. Laid-open No. Heisei 10-109520 discloses an air conditioner in which recirculation or fresh air is supplied in a two-layer air flow structure and which is provided with two foot vents and two foot doors for adjusting the degrees of opening of the foot vents. However, in this air conditioner, while recirculation and fresh air flows through the two-layer air flow structure, the mixing of air is deteriorated in an air mixing region for a temperature adjusting door positioned in front of a heater core, so the difference in temperature occurs between front and rear foot vent sides. When the mixing of air is deteriorated, a white fogging occurs while high-temperature, high-humidity fresh air, which flows into the air conditioner when a recirculation air suction mode is shifted to a fresh air suction mode, is mixed with low-temperature, low-humidity air around the evaporator.
Japanese Pat. Laid-open No. Heisei 10-181332 discloses an air conditioner in which two doors are rotatably and adjacently positioned, the rotation areas of the two doors are partly overlapped to form a seal surface at the stop position of doors. Additionally, various air conditioners are disclosed in Japanese Pat. Laid-open No. Heisei 10-181331, Japanese Pat. Laid-open No. Heisei 10-181336 and Japanese Pat. Laid-open No. Heisei 10-230734. However, these air conditioners are problematic in that the gap between a door and an evaporator is large at an recirculation air/fresh air partitioning position and the mixing of recirculation and fresh air is increased, thereby causing the same problems as the above-described air conditioners have.
In particular, the above-described air conditioners are problematic in that air discharge to the front and rear portions of the floor of an automobile cannot be controlled effectively.